Genetic improvement in cotton fiber elongation can impact yarn quality

Fiber quality is important to the textile industry because it directly relates to processing performance, productivity and yarn quality. For marketing purposes, the fiber quality of U.S. cotton is determined by the United States Department of Agriculture (USDA) classing offices using High Volume Instrument (HVI). HVI measures fiber length, length uniformity, strength, micronaire, color, leaf and extraneous matter. Recent research shows other fiber properties not included in the USDA classification should be considered when developing new cultivars to improve spinning performance, yarn quality, and market value. Fiber properties of interest include but are not limited to fiber maturity, short fiber content, fiber elongation, and work-to-break characteristics. Breeding for higher fiber elongation is expected to result in new cultivars that can withstand processing with less fiber breakage, perform better in spinning, and produce better yarn quality. The purpose of this research was to evaluate spinning performance and yarn quality of cotton lines developed to place emphasis on fiber elongation during the breeding process. Fifteen F2 populations were followed through a series of selections to the stage of "end product" by conducting spinning tests on F5 progeny lines. Divergent selection for fiber elongation was conducted in the F2 and F3 generations with nine lines being selecting in the F4 generation for spinning. Yarn properties and fiber properties of each line were evaluated together for correlations and potential trends. Yarn quality of experimental lines was also compared to yarn quality of a commercial check cultivar. Fiber and yarn data were evaluated to determine if and clarify how fiber elongation influenced spinning performance and yarn quality. It was determined that it is possible to improve fiber elongation through breeding and that by placing an emphasis on fiber elongation improvements can be made to overall fiber and yarn quality. Results also demonstrate the potential impact of disregarding fiber elongation or selecting genotypes with low fiber elongation; there were negative effects on both fiber and yarn. There is opportunity to indirectly address multiple fiber quality objectives and improve the end-product by placing selection pressure on this specific fiber characteristic during the breeding process.